Almost 1,800 commuters have been given refunds after Oyster readers charged the wrong card (Picture: PA)

Bus passengers have been wrongly charged thousands of pounds because of a quirk in the contactless payment system, Metro has learned.

Almost 1,800 commuters have been given refunds totalling £11,000 after Oyster readers charged the wrong card.

Some disgruntled Londoners end up paying for journeys twice, as money is taken from their debit cards despite the fact they have paid for a season ticket.

The figures – released following a Freedom of Information request – will prompt fears of more overpayments when the technology is rolled out across London transport later this year.

TfL director Shashi Verma said: ‘If a wallet or purse contains several cards, it is possible the reader will detect one card without seeing the other.’

Contactless payment was introduced on buses in 2012, allowing travellers to pay on bank cards without a Pin. The fare costs the same as on Oyster cards. More than 10million journeys have been made using contactless payment on London buses so far.

But there are potential consequences for those who are wrongly charged, as customers could be pushed beyond their overdraft or credit limit.

In some cases, the reader may detect two cards and reject them both, which is known as ‘card clash’.

TfL has started publicity campaigns at stations, reminding travellers to keep their cards separate.

Mr Verma added: ‘Just under one per cent of all Oyster and contactless journeys involve a card clash and we are seeing this number continue to drop each week.’